package com.wujie.section12;

/**
 * Created by wujieliu on 2017/11/1.
 */
public class RubberDuck implements Quackable {
    public void quack() {
        System.out.println("Squeak");
    }

    public void registerObserver(Observer observer) {

    }

    public void notifyObservers() {

    }
}
